Acid-fast bacilli are to be fractionated to yield cell walls which will be used for immunoprophylaxis of tumorigenesis due to melanoma B16 cells in C57Bl/6 mice. The cell walls will be suspended either in saline (WCW equals water cell walls) or suspended in Tween saline after treatment with mineral oil (Drakeol-6VR) (OCW equals oil cell walls) and a comparison will be made of their effect upon the initiation of melanoma tumors in mice. Mycobacterial whole cells will be exhaustively treated with organic solvents and the residues as well as the extractives will be tested for their ability to induce resistance to tumorigenesis. Waxes A, B, C and D will be extracted. Initial studies will be made of cell walls from BCG (Mycobacterium bovis), an attenuated acid-fast organism. Subsequent studies will be made of material from a nonpathogenic species, M. smegmatis (strain butyricum), a pathogenic bovine tubercle bacillis (M. bovis, strain Vallee) and M. kansasii. The methyl alcohol residue (MER) of phenol-killed organisms will also be prepared and studied. The effect of cortisone and of antithymocyte serum (ATS) upon the suppressive effect of the above materials will be studied. In addition studies of the presence of cell-mediated immunity and blocking antibodies will be made and the relation of the adjuvants mentioned above to the occurrence of these immune responses will be determined.